Structure of NanocrystallineTi3C2MXene Using Atomic Pair Distribution Function

Abstract

The structures of nanocrystalline pristine, potassium hydroxide and sodium acetate intercalated new two-dimensional materials ${\mathrm{Ti}}_3{\mathrm{C}}_2$ MXenes were studied using the x-ray atomic pair distribution function technique. Pristine MXene has a hexagonal structure with $a=b=3.0505(5)\AA$, $c=19.86(2)\AA$ (S.G. $P{6}_3/mmc$ No. 194). Both hydroxyl and fluoride terminating species are present. The intercalation of ${\mathrm{K}}^{+}$ or ${\mathrm{Na}}^{+}$ ions expands the ${\mathrm{Ti}}_3{\mathrm{C}}_2$ layers perpendicular to the planes but shrinks the in-plane $a$ and $b$ lattice parameters.